Palynology

Source: Wikipedia, the free encyclopedia.

Pine pollen under the microscope
trilete spores. Such spores provide the earliest evidence of life on land.[1]
Green: A spore tetrad. Blue: A spore bearing a trilete mark – the Y-shaped scar. The spores are about 30–35 μm across.

Palynology is the study of microorganisms and microscopic fragments of mega-organisms that are composed of acid-resistant organic material and occur in

Protista that have existed since the late Proterozoic.[2][3]

It is the science that studies contemporary and fossil

siliceous or calcareous tests. The name of the science and organisms is derived from the Greek Greek: παλύνω, translit. palynō, "strew, sprinkle" and -logy) or of "particles that are strewn".[3][4]

Palynology is an interdisciplinary science that stands at the intersection of

strata. Palynology is also used to date and understand the evolution of many kinds of plants and animals. In paleoclimatology, fossil palynomorphs are studied for their usefulness in understanding ancient Earth history in terms of reconstructing paleoenvironments and paleoclimates.[3][4]

Palynology is quite useful in disciplines such as

genera of plants. This not only provides important information on the ecology of honey bees, it also an important tool in discovering and policing the criminal adultriation and mislabeling of honey and its products. Forensic palynology uses palynomorphs as evidence in criminal and civil law to prove or disprove a physical link between objects, people, and places.[4][5]

Palynomorphs

Palynomorphs are broadly defined as the study of organic remains, including

Palynomorphs form a

fossiliferous. Palynomorphs, however, generally have been destroyed in metamorphic or recrystallized rocks.[6]

Typical palynomorphs include

chitinozoans. Palynomorph microscopic structures that are abundant in most sediments are resistant to routine pollen extraction.[6]

Palynofacies

A palynofacies is the complete assemblage of

sedimentary depositional environment can be used to learn about the depositional palaeoenvironments of sedimentary rocks in exploration geology, often in conjunction with palynological analysis and vitrinite reflectance.[7][8][9]

Palynofacies can be used in two ways:

History

Pollen core sampling, Fort Bragg, North Carolina

Early history

The earliest reported observations of pollen under a microscope are likely to have been in the 1640s by the English

who described pollen and the stamen, and concluded that pollen is required for sexual reproduction in flowering plants.

By the late 1870s, as optical microscopes improved and the principles of

(dinoflagellate cysts).

1890s to 1940s

Quantitative analysis of pollen began with

Earlier pollen researchers include Früh (1885),

Cromerian) from the harbour of Copenhagen.[18]
Lagerheim (in Witte 1905) and C. A.Weber (in H. A. Weber 1918) appear to be among the first to undertake 'percentage frequency' calculations.

1940s to 1989

The term palynology was introduced by Hyde and Williams in 1944, following correspondence with the Swedish geologist Ernst Antevs, in the pages of the Pollen Analysis Circular (one of the first journals devoted to pollen analysis, produced by Paul Sears in North America). Hyde and Williams chose palynology on the basis of the Greek words paluno meaning 'to sprinkle' and pale meaning 'dust' (and thus similar to the Latin word pollen).[19]

Pollen analysis in North America stemmed from Phyllis Draper, an MS student under Sears at the University of Oklahoma. During her time as a student, she developed the first pollen diagram from a sample that depicted the percentage of several species at different depths at Curtis Bog. This was the introduction of pollen analysis in North America;[20] pollen diagrams today still often remain in the same format with depth on the y-axis and abundances of species on the x-axis.

1990s to the 21st century

Pollen analysis advanced rapidly in this period due to advances in optics and computers. Much of the science was revised by Johannes Iversen and Knut Fægri in their textbook on the subject.[21]

Methods of studying palynomorphs

Chemical preparation

Chemical digestion follows a number of steps.

Acetolysis was developed by Gunnar Erdtman and his brother to remove these fine cellulose materials by dissolving them.[24] In acetolysis the specimen is treated with acetic anhydride and sulfuric acid, dissolving cellulistic
materials and thus providing better visibility for palynomorphs.

Some steps of the chemical treatments require special care for safety reasons, in particular the use of HF which diffuses very fast through the skin and, causes severe chemical burns, and can be fatal.[25]

Another treatment includes kerosene flotation for chitinous materials.

Analysis

Once samples have been prepared chemically, they are mounted on microscope slides using silicon oil, glycerol or glycerol-jelly and examined using light microscopy or mounted on a stub for scanning electron microscopy.

Researchers will often study either modern samples from a number of unique sites within a given area, or samples from a single site with a record through time, such as samples obtained from peat or lake sediments. More recent studies have used the modern analog technique in which paleo-samples are compared to modern samples for which the parent vegetation is known.[26]

When the slides are observed under a microscope, the researcher counts the number of grains of each pollen taxon. This record is next used to produce a

pollen diagram. These data can be used to detect anthropogenic effects, such as logging,[27] traditional patterns of land use[28] or long term changes in regional climate[29]

Applications

Palynology can be applied to problems in many scientific disciplines including

:

Because the distribution of

palaeoenvironmental reconstruction, one common and lucrative application of palynology is in oil and gas
exploration.

See also

  • Aperture (botany) – Areas on the walls of a pollen grain, where the wall is thinner and/or softer
  • Aeroplankton – Tiny lifeforms floating and drifting in the air, carried by the wind

References

  1. JSTOR 2396358
    .
  2. ^ a b c d Williams, G., Fensome, R.A., Miller, M. and Bujak, J., 2020. Microfossils: palynology. In Sorkhabi, R., ed., 15 pp., Encyclopedia of Petroleum Geoscience. Geneva, Switzerland, Springer Nature. 1000 pp.
  3. ^ a b c d Kneller, M., and Fowell, F., 2009. Palynology. In Gornitz, V., ed., pp. 766-768., Encyclopedia of Paleoclimatology and Ancient Environments. Geneva, Switzerland, Springer Dordrecht. 1049 pp.
  4. ^ Laurence, A.R., and Bryant, V.M., 2009. Forensic Palynology. In Bruinsma, G., and Weisburd, D., ed., pp. 1471-1754., Encyclopedia of Criminology and Criminal Justice. New York, New York, Springer Science+Business Media. 5632 pp.
  5. ^
  6. .
  7. .
  8. .
  9. ^ Bradbury, S. (1967). The Evolution of the Microscope. New York: Pergamon Press. pp. 375 p.
  10. ^ Jansonius, J.; D.C. McGregor (1996). "Introduction, Palynology: Principles and Applications". AASP Foundation. 1: 1–10. Archived from the original on 2007-07-09.
  11. ^ Traverse, Alfred and Sullivan, Herbert J. "The Background, Origin, and Early History of the American Association of Stratigraphic Palynologists" Palynology 7: 7-18 (1983)
  12. ^
    Blackwell Scientific Publications. Archived from the original
    on 2010-04-03.
  13. ^ a b Faegri, Knut (1973). "In memoriam O. Gunnar E. Erdtman". Pollen et Spores. 15: 5–12.
  14. ^ von Post, L (1918) "Skogsträdpollen i sydsvenska torvmosslagerföljder", Forhandlinger ved de Skandinaviske naturforskeres 16. møte i Kristiania 1916: p. 433
  15. ^ Früh, J (1885) "Kritische Beiträge zur Kenntnis des Torfes", Jahrb.k.k.Geol.Reichsanstalt 35
  16. ^ Trybom, F (1888) "Bottenprof fran svenska insjöar", Geol.Foren.Forhandl.10
  17. ^ Sarauw, G. F. L. (1897). "Cromer-skovlaget i Frihavnen og trælevningerne i de ravførende sandlag ved København" [The Cromer Forest layer in the Free Harbour and Wood Remains in the Amber containing strata near Copenhagen] (PDF). Meddelelser Fra Dansk Geologisk Forening / Bulletin of the Geological Society of Denmark (in Danish). 1 (4): 17–44.
  18. ^ Hyde, H.A.; D.A. Williams (1944). "The Right Word". Pollen Analysis Circular. 8: 6. Archived from the original on 2007-06-18.
  19. ^ Draper, Phyllis. "A DEMONSTRATION OF THE TECHNIQUE OF POLLEN ANALYSIS". {{cite journal}}: Cite journal requires |journal= (help)
  20. ^ Fægri, K. & Iversen, J. (1989) Textbook of pollen analysis. 4th ed. John Wiley & Sons, Chichester. 328 p.
  21. ^ Bennett, K.D.; Willis, K.J. (2001). "Pollen". In Smol, John P.; Birks, H. John B.; Last, William M. (eds.). Tracking Environmental Change Using Lake Sediments. Volume 3: Terrestrial, algal, and siliceous indicators. Dordrecht: Kluwer Academic Publishers. pp. 5–32.
  22. .
  23. ^ Erdtman, O.G.E. "Uber die Verwendung von Essigsaureanhydrid bei Pollenuntersuchungen". Sven. Bot. Tidskr. 28: 354–358.
  24. ^ "Hydrofluoric acid fatality in Perth - hazard alert". 1995-03-06. Retrieved 2011-12-18.
  25. S2CID 129797797
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  26. ^ Niklasson, Mats; Matts Lindbladh; Leif Björkman (2002). "A long-term record of Quercus decline, logging and fires in a southern Swedish Fagus-Picea forest". Journal of Vegetation Science. 13 (6): 765–774.
    S2CID 84934798
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  27. ^ Hebda, R.J.; R.W. Mathewes (1984). "Holocene history of cedar and native cultures on the North American Pacific Coast". Science. 225 (4663): 711–713.
    S2CID 39998080
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  28. .

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External links